ArrayPower: Solar panels meet distributed conversion

Solar panels need to be attached to devices that convert their current from direct current (DC) to alternating current (AC) to be used by a home or to feed the grid. Sounds like a pretty standard process right? Well a startup called ArrayPower (formerly Array Converter) has engineered a new way to do the process by distributing conversion between multiple solar panels, and the technology promises to deliver more power at the price of conventional power conversion electronics, according to ArrayPower’s CEO, Wendy Arienzo.

Arienzo is divulging more details about the company’s technology after giving a short and cryptic description of it at a cleantech conference last week. The technology makes use of pulse amplitude modulation, a concept that has been used in Ethernet equipment and in controlling LED lighting, but now is being applied to solar. ArrayPower, which is based in Sunnyvale, Calif. and founded in 2007, has also lined up $22 million in venture capital funding.

Here’s how it works: each ArrayPower silicon-based device is attached on the back of a solar panel to boost the voltage of the direct current from 60 volts to 208 volts before being connected to three circuits of resistors and capacitors, which send out the current in pulses. Those pulses alone aren’t enough to form the current with the right frequency for an electric grid. But when combining at least four of them, you have the right AC wave to supply to the grid.

“It’s like a symphony where you have different instruments playing and they all come together,” she said.

Conventional power conversion devices are called inverters, and each produces AC at the right frequency. Each inverter typically is paired with about a dozen solar panels, though startups have emerged in recent years to develop microinverters that go on the back of each solar panel. Microinverters can better monitor and adjust the power output of each solar panel, and as a result promise to reduce power losses. But microinverters are also newer products to the market and more expensive than centralized inverters.

ArrayPower’s device, which the company calls a “sequenced inverter,” promises to offer the benefits of microinverters (more power harvested) at the price of centralized inverters, Arienzo said. That’s the idea anyway, since the company hasn’t shipped its products commercially yet. It intends to sell them to solar panel makers, who will assemble them into the panels, and it has lined up one customer who will launch an integrated panel at the Solar Power International conference in Texas later this month. ArrayPower expects to start shipping its devices early next year and will hire a contract manufacturer to produce them.

The U.S. will be the first market, though the company is doing field trials of its gear in Germany to get ready for the commercial launch in Europe. The company’s investors include Partech International, Trident Capital, Draper Fisher Jurvetson and Firelake Capital Management. ArrayPower’s chairman is Kevin Surace of Serious Energy, and its board includes Solaria’s CEO, Dan Shugar.